"No true Scotsbertarian"
How many times have you heard- or written- "No real libertarian would ever...."? Did someone throw the "No true Scotsman" fallacy in the mix right away? Did it actually apply?
Because it often doesn't.
If you say "no true Scotsman can survive a complete decapitation", or "no true Scotsman is native to the Moon" then you'd be correct. By definition. It's not the same as saying "no true Scotsman would wear pink socks".
I've seen that fallacy called into play when someone says "no libertarian can be in favor of any form of taxation" or "no libertarian can support the 'troops'"
Yet, it is accurate to say that "no true Scotsman can flap his arms and fly to the moon", because any creature which could do that would not be human. By definition he could not be a "true Scotsman".
So it is with the "pro-tax libertarian"- taxation is theft and is enforced by violating the ZAP, and the same goes for military "service". Since the ZAP is the definition of "libertarian", no one can support those things and be a libertarian. At least not a consistent one.
But, if someone claims "no real libertarian would use a public library", then you'd be correct in calling this a "no true Scotsman" fallacy. There is no wrong in using what you are forced to pay for, as long as you don't advocate the continuation of the theft. There will be a difference of opinion from person to person, and neither side is automatically eliminated from the category of "real libertarian".
Just because I apply a label to myself doesn't make the label accurate. If I fit the definition, then I am what I say. If I don't, then I am something other than what I claim to be. And, that's fine. People get confused over what words mean all the time. It's not worth fighting over. If you don't fit the definition, find where you do fit and correct what you call yourself. But if you are not a Scotsman, don't be offended when someone points it out.